var person={};
person.name = "anna";
person.age=18;
person.say=function(){
    console.log("my name is anna!");
}
console.log(person);
var arr = [1,3,4,5];
console.log(arr);

function show(){

}
console.log(show);

var date = new Date();
console.log(date);

console.log("==========================================");
var o = new Object();
var arr = new Array(1,2,3,4);
var fun=new Function("a","b");
console.log(o);
console.log(arr);
console.log(fun);
console.log(o.toString());
console.log(arr.toString());
console.log(fun.toString());
console.log("==========================================");
console.log(o.valueOf());
console.log(arr.valueOf());
// console.log(fun.valueOf());

console.log("======================rewrite====================");
var obj = new Object();
obj.valueOf = function(){
    return "this is obj's valueof"
}
obj.toString = function(){
    return "this is obj's tostring"
}
console.log(obj.valueOf());
console.log(obj.toString());








